1. Field of the Invention
This invention relates generally to signal oscillators and more particularly to microwave and millimeter wave oscillators comprised of dielectric resonators.
2. Description of the Prior Art
While dielectric resonators for microwave integrated circuits are well known, a relatively new dielectric resonator having relatively good temperature stability is disclosed in a publication entitled, "A Proposal of a New Dielectric Resonator Construction for MIC's", by Y. Shimoda, et al. which appeared in the IEEE Transactions On Microwave Theory And Techniques, Vol. MTT-31, No. 7, July, 1983 at pp. 527-532. There a dielectric resonator is disclosed consisting of a cylindrical dielectric resonator element mounted on a stripline substrate by a relatively low loss dielectric mounting element. A dielectric disc having a thin metal film applied to its upper surface is affixed to the top of the resonator element. Adjustment of the operating frequency is achieved by trimming a portion of the metallized film area from the top of the dielectric disc. Such a device, however, still nevertheless exhibits resonant frequency changes as a function of temperature.
Accordingly, it is an object of the present invention to provide an improvement in a source of microwave and millimeter wave signals.
It is another object of the invention to provide an improvement in a dielectric resonator for generating microwave and millimeter wave signals.
It is still another object of the invention to provide a dielectric resonator having improved frequency stabilization as a function of temperature.
A further object of the invention is to provide for a dielectric resonator having a zero temperature coefficient.
And still a further object of the invention is to provide an improvement in the means for tuning the dielectric resonators.